1. Field of the Invention
The present invention relates to methods and apparatus for handling tubulars using top drive systems. Particularly, the invention relates to methods and apparatus for adapting a top drive for use with running and rotating tubulars. More particularly still, the invention relates to a tubular handling apparatus for engaging with a tubular and rotating the same.
2. Description of the Related Art
It is known in the industry to use top drive systems to rotate a drill string to form a borehole. Top drive systems are equipped with a motor to provide torque for rotating the drilling string. The quill of the top drive is typically threadedly connected to an upper end of the drill pipe in order to transmit torque to the drill pipe. Top drives may also be used in a drilling with casing operation to rotate the casing.
In order to drill with casing, most existing top drives require a threaded crossover adapter to connect to the casing. This is because the quill of the top drives is not sized to connect with the threads of the casing. The crossover adapter is designed to alleviate this problem. Typically, one end of the crossover adapter is designed to connect with the quill, while the other end is designed to connect with the casing.
However, the process of connecting and disconnecting a casing is time consuming. For example, each time a new casing is added, the casing string must be disconnected from the crossover adapter. Thereafter, the crossover must be threaded into the new casing before the casing string may be run. Furthermore, this process also increases the likelihood of damage to the threads, thereby increasing the potential for downtime.
There is a need, therefore, for methods and apparatus for adapting the top drive for engaging and rotating a tubular such as casing.